Add a new layer to show the sightings of the invasive zebra mussels. In Construct mode, switch to the "Invasive Species" Data Library. Double click the Layer's name "Zebra Mussel" and it will automatically be added to the top of the Layer List.

Zebra mussels are small shellfish named for the striped color of their shells. They typically attach to objects by threads on their shells. The zebra mussel is native to the Black, Caspian, and Azoz Seas. They were first described in Europe, by Pallas, in 1769.

Zebra Mussel

Zebra mussels were first discovered in the Great Lakes of North America in 1988. It is likely that their introduction was due to a ballast exchange from a cargo ship. By 1990 they had spread rapidly to all of the Great Lakes. Soon thereafter they escaped to the Illinois and Hudson Rivers, eventually moving into the Mississippi River system. By 2008, Zebra Mussels had spread across the United States, all the way to California.

Zebra mussels are a significant invader because they can spread both in and out of the water. In their freshwater habitat they can disperse in all life stages. They are prolific biofouling agents and therefore have profound effects on water supply pipes, including nuclear power plant cooling intake pipes. Not only do they damage man made structures, they are disruptive to entire food webs. Zebra mussels primarily consume phytoplankton. Additionally, they consume other suspended materials in the water column. Consequently, areas with dense invasions of zebra mussels have unusually transparent water. In fact, during the invasion of zebra mussels in Saginaw Bay, Michigan the sampling areas experienced a 60-70% reduction in Chlorophyll –a concentrations.

Find A Feature By Its Attributes

The Find tool is a quick way to locate a feature. However, this type of search works best if you know how to spell, and capitalize, what you are looking for. top of page

Find the first zebra mussels in record from Ohio.

In to Visualize mode,

Make Zebra Mussel the active layer by clicking once on its name in the Layer List.

Click once on the Zebra Mussel label in the Layer List. Then click the Show Table of Active Layer button. Spend some time looking through the fields and data records that are in the table. Use the scroll bars to move up and down and across the table. Look carefully at the STATE abbreviations.

Use the Legend to find the U.S. State of Ohio

Turn on the Legend for the layer U.S. States by clicking the L symbol next to the words "Category List". On the legend for the layer U.S. States, click on the state name, Ohio. The state will be highlighted in yellow and a selection will show up in the Layer List.

Make the selection active by clicking the radio button next to its name and click the Zoom to Selection button to Zoom into the new selection for a closer look.

Find all the zebra mussels sighted in the year 1988

Switch to Analyze mode, by clicking the tab. A new window opens the window is pictured below. It may be empty at first until you begin your selections.

In the Analyze window click Select ... > By Value . Set up the query to find records in the "Zebra Mussel" layer, that occurred in the year 1988. Do NOT make this selection a new layer; leave it as a subset of the original layer.

Use the pull down menus to Select Records from: Zebra Mussel, Whose YEAR is before 1989 CE and is On or After 1988 CE. To change the years click in the box with the year value and either use the up and down arrows or re enter the year value by typing in the new year.

Name the Result – Zebra Mussel 1988. Click OK.

Five records are selected on the map and highlighted in the table of the selection.

On the layer name, in the Highlight Mode drop down, change the mode from "Color Selected Yellow" to "Hide Unselected".

This selection should process have yielded only 1 result.
Note: the "and" phrase in the middle of the Analyze window. It appeared when you clicked the "+" button. Querying is like setting up math equations or writing sentences. If you are confused, try reading your query out loud and see if it makes sense. This one reads "Show me the Zebra Mussel records whose Year is 2005 and whose State is New York. "
This image shows the query results in the table of selection and on the map. There is one dot in NY. To see it, choose the hide unselected highlight mode. Click on the image below for a larger view.

Set up a query to find a set of zebra mussels within the date range between 1997 and 2000.

The equation is Whose Year is before 2001 CE and Is On or After 1997.
This image shows the query results on the map. In the table 808 records match the query and are highlighted in yellow on the map and listed in the table of the selection.

The equation (YEAR < 1989) shows that 5 zebra mussels were documented by the end of 1988.
The statement Whose: YEAR is Before 1990 and On or after 1987, shows that 20 zebra mussels were documented by the end of 1989.
The equation YEAR is Before 2000 and On or After 1987 shows that 2354 zebra mussels were documented by the end of 1999.

This query yields 95 records because it gives you BOTH records that are either in the county of Ashtabula or that are in the State of Ohio. The expression "OR" is more inclusive than the operator "AND".

In the U.S. Rivers layer, try this equation that combines both set and Boolean algebra.
Whose SYSTEM is Mississippi AND Whose LENGTHCOMP Greater than or Equal to 1361.4323989
What question does this query answer?

The wildcard symbol % combined with the expression LIKE allows you to set up a query that is a bit more open ended. Enter this equation in the Query Builder In the U.S. States layer:
NAME Starts with A
What result do you get and why?

Build Your Own Database Query and Take a Screenshot

Design and execute a query of interest to you or that you might use in your teaching. Here are a few suggestions.

Try selecting the U.S. Rivers, by Name, Length or System.

Select a Lake or River in your State.

Select your own State.

Select and combine attributes from the U.S. States layer such as population, number of farms, crop acreage or other demographic data.

Once you have built and executed a query, take a screenshot of the map and the Analyze window. In your discussion group, post the question you asked, the statement you used, and the result of your query along with the screenshots. These are the screenshots that are needed for your required weekly activity.

Follow the instructions below to make a screen shot:

On a Windows computer, press Alt and Printscreen at the same time. This will save an image of the screen to the computer's clipboard. Launch Paint and choose Edit > Paste. Save the image as a jpeg, giving it a name that describes it, such as River_query.jpg.

On a Mac computer, press Command-Shift-4 (Command key = Apple key) all at the same time and drag a box over the area of the screen that you want to capture. This will produce a file named Picture1.png on your desktop. Move Picture1.png to your Week 5 folder or to a place where you can easily find it. Double click on the file to open it in Preview. Rename the image and save it as a jpeg, giving it a name that describes it, such as River_query.jpg.